OBJECTIVE: To explore the genetic basis of two fetuses with an osteogenesis imperfecta (OI) phenotype. METHODS: Two fetuses diagnosed at the Affiliated Hospital of Weifang Medical College respectively on June 11, 2021 and October 16, 2021 were selected as the study subjects. Clinical data of the fetuses were collected. Amniotic fluid samples of the fetuses and peripheral blood samples of their pedigree members were collected for the extraction of genomic DNA. Whole exome sequencing (WES) and Sanger sequencing were carried out to identify the candidate variants. Minigene splicing reporter analysis was used to validate the variant which may affect the pre-mRNA splicing. RESULTS: For fetus 1, ultrasonography at 17+6 weeks of gestation had revealed shortening of bilateral humerus and femurs by more than two weeks, in addition with multiple fractures and angular deformities of long bones. WES revealed that fetus 1 had harbored a heterozygous c.3949_3950insGGCATGT (p.N1317Rfs*114) variant in exon 49 of the COL1A1 gene (NM_000088.4). Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), it was classified as a pathogenic variant (PVS1+PS2+PM2_Supporting) for disrupting the downstream open reading frame resulting in premature translational termination, being de novo in origin, and lacking records in the population and disease databases.For fetus 2, ultrasonography at 23 weeks of gestation also revealed shortening of bilateral humerus and femurs by one and four weeks, respectively, in addition with bending of bilateral femurs, tibias and fibulas. Fetus 2 had harbored a heterozygous c.1557+3A>G variant in intron 26 of the COL1A2 gene (NM_000089.4). Minigene experiment showed that it has induced skipping of exon 26 from the COL1A2 mRNA transcript, resulting in an in-frame deletion (c.1504_1557del) of the COL1A2 mRNA transcript. The variant was inherited from its father and had been previously reported in a family with OI type 4. It was therefore classified as a pathogenic variant (PS3+PM1+PM2_Supporting+PP3+PP5). CONCLUSION The c.3949_3950insGGCATGT (p.N1317Rfs*114) variant in the COL1A1 gene and c.1557+3A>G variant in the COL1A2 gene probably underlay the disease in the two fetuses. Above findings not only have enriched the mutational spectrum of OI, but also shed light on the correlation between its genotype and phenotype and provided a basis for genetic counseling and prenatal diagnosis for the affected pedigrees.
Pregnancy ; Female ; Humans ; Osteogenesis Imperfecta/genetics* ; Collagen Type I, alpha 1 Chain ; Collagen Type I/genetics* ; Mutation ; Fetus

OBJECTIVETo study a family affected with osteogenesis imperfecta for potential mutations in COL1A1 gene.

METHODSClinical data of an affected family was collected. Potential mutation of the COL1A1 gene was screened using polymerase chain reaction and direct sequencing. Suspected mutation was detected in 20 unaffected relatives and 200 unrelated healthy controls.

RESULTSAnalysis of RNA splicing has revealed a c.3208G/A mutation, which created a new splice sites and led to a frameshift mutation. The same mutation was not detected in the unaffected relatives or the 200 healthy controls.

CONCLUSIONMutations of the COL1A1 gene are one of the major causes of osteogenesis imperfecta in Chinese population. Our finding has enriched the mutation spectrum of type I collagen genes.

Adult ; Child, Preschool ; Collagen Type I ; genetics ; Female ; Humans ; Male ; Mutation ; Osteogenesis Imperfecta ; genetics ; RNA Splicing

OBJECTIVEThe aim of this study was to investigate the expression of collagen in the process of masseter muscle reattachment to the cortical and cancellous bones of mandible.

METHODSA total of nine adult goats were used in the study. One was the control. The other eight were treated with bilateral detachment of the masseter muscles. The biopsies of bone and muscle were taken at 2, 4, 8 and 12 weeks after the operation. The characteristics of the healing muscle-bone interfaces were examined using immunohistochemical techniques.

RESULTSImmunohistochemical analysis illustrated that the locations of collagen type I, II and III were different during the healing process, but similar in the cortical and cancellous bones.

CONCLUSIONThis study demonstrates that the distribution of the three types of collagens at the muscle-bone interfaces is associated with time, but not related with their locations.

Animals ; Collagen ; biosynthesis ; genetics ; Collagen Type I ; biosynthesis ; genetics ; Collagen Type II ; biosynthesis ; genetics ; Collagen Type III ; biosynthesis ; genetics ; Female ; Goats ; Male ; Mandible ; metabolism ; pathology ; surgery ; Masseter Muscle ; metabolism ; pathology ; surgery ; Wound Healing ; physiology

Cartilage is regularly needed for reconstructive surgery. Basic research in tissue engineering is necessary to develop its full potential. We presented here the expression profile of type II collagen gene and type I collagen gene in human auricular monolayer culture expansion. Cultured chondrocytes documented a reduction in the expression level of collagen type II gene whilst collagen type I gene was gradually expressed through all the passages. This study demonstrated that human auricular chondrocytes lose its phenotypic expression during monolayer culture expansion. Further studies are required to enhance cartilage specific gene expression, collagen type II throughout the in vitro culture.
Cells, Cultured ; Chondrocytes/*cytology ; Collagen Type I/*genetics ; Collagen Type II/*genetics ; Ear, External ; Fibroblasts/cytology ; *Phenotype ; Reverse Transcriptase Polymerase Chain Reaction ; Tissue Engineering/*methods

Adult ; Asian Continental Ancestry Group ; genetics ; Collagen Type I ; genetics ; Humans ; Mutation ; Osteogenesis Imperfecta ; genetics ; Pedigree ; Perinatal Death

OBJECTIVE: To analyze the clinical phenotype of six pedigrees affected with osteogenesis imperfecta and their genetic basis. METHODS: Peripheral blood or abortic tissues of the six pedigrees were collected for the extraction of genomic DNA. Next generation sequencing (NGS) was carried out to detect pathological variants in the genome. Sanger sequencing was used for validating suspected variant among the six pedigrees and 100 healthy controls. RESULTS: In pedigree 1, the proband and his daughter both carried a heterozygous c.1976G>C variant of COL1A1. The probands in pedigrees 2 to 6 respectively carried heterozygous variants of c.2224G>A of COL1A2, c.2533G>A of COL1A1, c.2845G>A of COL1A2, c.2532_2540del of COL1A1, and c.1847G>A of COL1A2. The same variants were not detected in their parents and the 100 healthy controls. CONCLUSION Variants of COL1A1/2 gene probably underlie the pathogenesis for osteogenesis imperfecta in these pedigrees. Discovery of the nevol variants has enriched the spectrum of COL1A1/2 gene variants and facilitated genetic counseling and prenatal diagnosis for the affected pedigrees.
Collagen Type I ; genetics ; Female ; Genetic Variation ; Genotype ; Humans ; Male ; Mutation ; Osteogenesis Imperfecta ; genetics ; Pedigree ; Phenotype ; Pregnancy

AIMTo observe the effects of hypoxia on DNA synthesis and the expression of collagen type I and III mRNA in cultured adult rat cardiac fibroblasts.

METHODSCardiac fibroblasts(CFs) were isolated from adult Wistar rat ventricule and cultured in vitro either in normoxic or hypoxic condition. Studies were conducted with the second passage of CFs. The changes of DNA synthesis was determined by measuring the incorporation of 3H-TdR into DNA and the changes of expression of pro-alpha1 (I) collagen, pro-alpha1(III) mRNA were measured by in situ hybridization respectively.

RESULTSThe 3H-TdR incorporation of CFs was increased by 34% (P < 0.05) and 36% (P < 0.01) after 6 h, 12 h hypoxia (2% O2) exposure respectively. The level of pro-alpha1(I) collagen mRNA expression was significantly elevated in the cells under hypoxia for 4 h, 8 h, and 12 h. The expression of pro-alpha1(III) mRNA increased when cells were cultured under hypoxia for 2 h.

CONCLUSIONThese results suggest that hypoxia alone can upregulate DNA synthesis and expression of collagen type I and III mRNA in adult rat cardiac fibroblasts. It may be one of the important mechanisms by which hypoxic myocardial fibrosis occur.

Animals ; Cell Hypoxia ; Cells, Cultured ; Collagen Type I ; metabolism ; Collagen Type III ; metabolism ; DNA ; biosynthesis ; Fibroblasts ; metabolism ; Male ; Myocytes, Cardiac ; cytology ; RNA, Messenger ; genetics ; Rats ; Rats, Wistar

OBJECTIVETo characterize the role of Smads proteins in alpha 2 (I) collagen (COL1A2) gene expression induced by bone morphogenetic protein-2 (BMP-2) in odontoblast cell line MDPC-23.

METHODSEndogenous Smad protein expression was determined by immunocytochemistry. Smads function and their role in COL1A2 gene expression were investigated in cotransfection experiments using promoter-luciferase reporter gene construct.

RESULTSMDPC-23 cells expressed Smad1, Smad5 and Smad6. BMP-2 promoted the activation of COL1A2 promoter reporter construct. Transient overexpression of Smad1 or Smad5 was enhanced, while overexpression of Smad6 inhibited BMP-2-induced COL1A2 promoter activity. BMP-2 inducibility could be blocked by overexpression of Smad1 or Smad5 dominant negative mutant.

CONCLUSIONSSmad signaling is functioning and appears to be involved in BMP-2-induced COL1A2 collagen transcription in MDPC-23. Smad signaling may play an important role in odontoblast differentiation and dentin extracellular matrix formation mediated by BMP-2.

Animals ; Bone Morphogenetic Protein 2 ; Bone Morphogenetic Proteins ; genetics ; Cell Line ; Collagen ; genetics ; Collagen Type I ; Mice ; Odontoblasts ; cytology ; metabolism ; Smad Proteins ; physiology ; Transforming Growth Factor beta ; genetics

Osteogenesis imperfecta (OI) comprises a heterogeneous group of disorders characterized by bone fragility, frequent fractures, and low bone mass. Dominantly inherited COL1A1 or COL1A2 mutations appear to be causative in the majority of OI types, but rare recessively inherited genes have also been reported. Recently, SERPINF1 has been reported as another causative gene in OI type VI. To date, only eight SERPINF1 mutations have been reported and all are homozygous. Our patient showed no abnormalities at birth, frequent fractures, osteopenia, and poor response on pamidronate therapy. At the time of her most recent evaluation, she was 8 yr old, and could not walk independently due to frequent lower-extremity fractures, resulting in severe deformity. No clinical signs were seen of hearing impairment, blue sclera, or dentinogenesis imperfecta. In this study, we describe the clinical and radiological findings of one Korean patient with novel compound heterozygous mutations (c.77dupC and c.421dupC) of SERPINF1.
Bone Density/genetics ; Child ; Collagen Type I/genetics ; Eye Proteins/*genetics ; Female ; Fractures, Bone/genetics ; Humans ; Nerve Growth Factors/*genetics ; Osteogenesis Imperfecta/diagnosis/*genetics ; Serpins/*genetics

Antisense Elements (Genetics) ; Cell Line ; Cell Proliferation ; Collagen Type I ; biosynthesis ; Genetic Therapy ; Hepatic Stellate Cells ; cytology ; metabolism ; Humans ; RNA, Messenger ; genetics ; Receptor, Angiotensin, Type 1 ; genetics ; Transfection